Installation guide

AC-215 Single and Double Door Access Control Unit
Hardware Installation Guide
16
RS485 Connection to the PC
Up to 32 ACU's can be linked together and connected to a single communication port on the
PC.
The RS485 interface must be used when multiple controllers are connected. The serial port
used to control the ACU is assigned in the Veritrax software Network Properties dialog box.
ACU supports the two-wire RS485 interface. RS485 interface enables the distance between
the ACU and PC to be extended up to 4000 feet (1300) meters. The data line wiring must be
in daisy chain formatting with one control unit following another. The first ACU connecting to
the PC must use the MD14 RS485 to RS232 adaptor.
" Daisy Chain
Communication lines must be wired in daisy chain format with one ACU following another.
!
J1 must be in the left position.
" Termination Resistors
At each end of the data line a termination resistor of 130 ohm is required across the L1 and L2
connections.
4321
4321
4321
ACU #1
J1 left position
ACU #2
J1 left position
ACU #3
J1 left position